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CVE-2026-121966Traefik before 2.11.60 and 3.7.16 ForwardAuth NTLM/Negotiate Identity Leak
Traefik 2.x before 2.11.60 and 3.x before 3.7.16 sends ForwardAuth subrequests (and, in 3.7, Ingress NGINX auth-url requests) through an auth-server connection pool shared by all clients, exposing connection-bound NTLM or Negotiate authentication. An unauthenticated attacker can reuse another user's authenticated connection, receiving the victim's identity via authResponseHeaders to access backends as that user.
7.0 HIGHEPSS 0.33%Not in KEVNVD: Awaiting Analysis
Overview
Severity
| Score | Severity | Version | Vector String |
|---|---|---|---|
| 7.0 | HIGH | 4.0VulnCheck (CNA) | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N |
| 8.7 | HIGH | 3.1VulnCheck (CNA) | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N |
Details
- CVE ID
- CVE-2026-121966
- Status
- Awaiting Analysis
- Assigner (CNA)
- VulnCheck
- Published
- Nov 4, 2026
- Last modified
- 2026-11-04 19:17 UTC
- Weaknesses
- CWE-488 · Exposure of Data Element to Wrong Session
Affected Products
As published by the CNA in the CVE record.
traefiktraefik1 version range
- before 2.11.60
traefiktraefik1 version range
- 3.0.0 before 3.7.16